Field of the Invention
The present invention relates to a helium vessel port arrangement and a helium vessel arrangement for magnetic resonance imaging (MRI) systems, especially for superconducting magnet systems with a helium cooling system. It further relates to a method for operating the helium vessel port arrangement.
Description of the Prior Art
Magnetic resonance imaging (MRI) systems typically comprise superconducting magnets and a helium cooling system. In the helium cooling system the gaseous helium is recondensed by means of a coldhead and guided into a helium vessel.
To exchange the coldhead the magnet has to be ramped down because the coldhead sock is connected to the helium vessel by a pipe. Failure to do this could, in the event of a quench result in a dangerous amount of helium gas escaping into the region of the Service Engineer carrying out the cold head exchange.
Furthermore, during coldhead exchange there is a risk of air ingress and subsequent ice build-up in the coldhead sock and connecting pipe. During the life of the magnet ice can collect in the pipe connecting the coldhead sock to the turret which is difficult to remove. The removal of the coldhead is necessary to carry out the de-ice operation which also requires the magnet to be ramped down. Currently in order to exchange a coldhead it has been necessary to ramp the magnet down. Also in order to de-ice the connecting pipe it has been necessary to ramp the magnet down and remove the coldhead.